Blough P M, Blough D S
J Exp Anal Behav. 1968 Jan;11(1):23-7. doi: 10.1901/jeab.1968.11-23.
Three pigeons' pecks were reinforced on 1- and 2-min variable-interval schedules, and frequency distributions of their interresponse times (IRTs) were recorded. The conditional probability that a response would fall into any IRT category was estimated by the interresponse-times-per-opportunity transformation (IRTs/op). The resulting functions were notable chiefly for the relatively low probability of IRTs in the 0.2- to 0.3-sec range; in other respects they varied within and between subjects. The overall level of the curves generally rose over the course of 32 experimental hours, but their shapes changed unsystematically. The shape of the IRT distribution was much the same for VI 1-min and VI 2-min. The variability of these distributions supports the notion that the VI schedule only loosely controls response rate, permitting wide latitude to adventitious effects. There was no systematic evidence that curves changed over sessions to conform to the distribution of reinforcements by IRT.
三只鸽子的啄击行为在1分钟和2分钟的可变间隔时间表上得到强化，并记录了它们的反应间隔时间（IRT）的频率分布。通过每次机会的反应间隔时间转换（IRTs/op）来估计反应落入任何IRT类别的条件概率。得到的函数主要特点是在0.2到0.3秒范围内IRT的概率相对较低；在其他方面，它们在不同个体之间和个体内部有所变化。曲线的总体水平在32个实验小时的过程中通常会上升，但它们的形状变化没有规律。1分钟可变间隔和2分钟可变间隔的IRT分布形状大致相同。这些分布的变异性支持了这样一种观点，即可变间隔时间表只是松散地控制反应率，允许偶然因素有很大的影响范围。没有系统的证据表明曲线在不同的实验时段会发生变化以符合按IRT分布的强化情况。
